Modification of alkyd resins



- atented V 5, rest No Drawing. Application Dctober 12, 1942,

Serial No. 461,799

3 Claims. (Cl. 260-22) Gamer. FIELD or INVEN ION AND STATEMENT or Owners This invention relates to the treatment of alkyd resins with modifying agents, whereby to alter the properties and characteristics of such resins. The present application is a continuation-in-part of my copending applications Serial No. 318,650, filed February 12, 1940, now Patent 2,298,270, issued October 13, 1942, and Serial No. 386,371, filed April 1, 1941, now Patent 2,311,200,- issued February 16, 1943.

Alkyd resins are of many types, all being esters, most commonly esters of polyhydric alcohols, such as glycerine, with mixtures of monobasic and polybasic acids,

Other polyhydric alcohols may also be used in the preparation of the alkyds, such as glycols, pentaerythritol, mannitol, sorbitol, etc.

Most usually, the polybasic acids are phthalic acid and maleic acid, commonly used in the form of their anhydrides. However, other polybasic acids and anhydrides are also sometimes used in alkyd resin manufacture.

The monobasic acids usually employed in alkyd resin manufacture are th high molecular fatty acids and/or natural resin acids, such as rosin.

The alkyd resins may be classified in various different ways depending upon their constituents and properties and for some purposes certain characteristics are important, while for other purposes, other characteristics are important. v

For instance, the esters of maleic acid and phthalic acid with glycerine are infusible and insoluble in organic solvents, after they have been heated for some time at elevated temperatures. Such esters yield only brittle films, in view of which for some purposes, it is of impor= tance to employ combined esters of polybasic acids and monobasic acids, in preparing alkyd resins. The monobaslc acids employed, for instance, fatty acid and/or resin acid, impart improved solubility characteristics to the alkyds so that they may readily be dissolved in organic solvents, and thereafter used to advantage in the coating arts.

Alkyds containing relatively high percentages of phthalic anhydride or other polybasic acids are harder and less soluble in organic solvents than alkyds containing a larger proportion of fatty acid and/or resin acid. The type otalkyd containing larger proportions of polybasic acid are commonly referred to as short oil alkyds, the other type usually being identified as "long oil alkyds.

The medium or long oil alkyds yield elastic and tough coatings and are important ingredients of various coating compositions.

In considering the nature of the alkyds to which the present invention is applicable, it might further be mentioned that various alkyd resins are sometimes classified according to their drying'characteristics. Thus, some alkyds are non-drying, som are semi-drying and baking alkyds, and some are air drying alkyds. Usually fatty acids of non-drying oils, such as fatty acids of castor oil, coconut oil and babassu oil, yield non-drying alkyds. On the other hand,

when employing fatty acids of semi-drying oils,

suchas sunflower oil and soya bean oil, the alkyds secured are semi-drying alkyds, useful for baking finishes and other purposes. Employment of fatty acids of drying oils, such as those of tu'ng 'oil, linseed oil and dehydrated castor oil, yield alkyds having air drying properties.

Although various procedures have been employed in the production of alkyds, and although many different catalysts have been employed in alkyd resin manufacture, I have found that the preformed alkyds-may be treated according to the p'resent'invention, thereby modifying the ,physical and/or other characteristics of the alkyds. For instance, the physical consistency may be changed appreciably, as may also the acid value and other properties.

In referring to changes in characteristics and properties, and in making comparisons of the modified alkyd resins with resins not treated with modifying agents as used in the present process, it is to be understood that the statement regarding changes and comparisons are always made on the basis of a relation between the product treated with a modifying agent and a product treated in exactly the same manner, heating, etc., but without a modifying agent. The latter is often herein referred to as a blank or control experiment.

As is mentioned in my copending applications above referred to and also in others referred to hereinafter, I believe alkyd resins to be organic isocolloids, i. e., colloidal systems in which the dispersed phase and the dispersion medium are both of the same chemical composition though present in different physical states.

At least most of the alkyds containing-fatty acids behave similarly under treatment according to the present invention, as do fatty oils, many examples of fatty oil treatment with modi fying agents being disclosed in copending applications. elsewhere referred to herein.

erties being of especial importance in coating compositions such as paints and the like.

The nature of the modifying agents employed according to the invention is considered Just below but it is here first pointed out briefiy that the process involves dispersion oi the modifying agent in the alkyd resin and heating the mixture for a time suflicient to alter the properties, as will further appear.

Tm: Moon'rmo Adm As is mentioned in my copending applications above identified, I believe that the colloidal system of organic isocolloids may be modified by means of modifying agents. According to the invention. such modiivlng agents are polar compounds in general. By polar compounds I mean compounds having polarityiin the molecule, thus inc uding electrolytes. Examples are given below.

Polar compounds are of many different classes,

many of which are defined in my copending applications. The type 01' modification secured by various groups of modifying agents and even by individual agents, may be quite different, many agents and groups producing'results which are quite distinctive, although as before mentioned, I believe the polar compounds are: all capable of influencing the colloidal system of alkyd resins in various of the respects already mentioned, and also-in others.

One particular general classification of polar compounds is as follows:

Metal salts of inorganic acids Metal salts of organic acids Inorganic acids Organic acids Metallo-organic compounds Metal alcoholates Aryl-metal compounds Organic esters oi inorganic acids Inorganic salts of organic bases Organic esters Amines also constitute a useful class, particularly the poly-amines, for instance, diamines. Examples of amines are benzidine, diphenylamine and alpha-naphthyl-amine.

Many oi the compounds falling in certain classes mentioned above are also of the type which I have termed two-radical compounds, 1. e., compounds having within the molecule an acidic inorganic residue and an organic residue. 'By an acidic inorganic residue I mean a residue capable of yielding an inorganic acid upon the addition of one or more hydrogen atoms, OH groups, or water molecules, or upon the application of heat.

Such two radical type compounds may desirably contain a sulpho-, haloor nitrogroup.

. Cations Typical examples of certain of the foregoing classifications are given Just below:

' Metal salts of me ento acids (Formed by various combinations oi the following:)

Cations Anions Ammonium Chloride Lithium Bromide Sodium Iodide Barium Carbonate-Bicarbonate Calcium Sulphate Zinc Bisulphate Iron Sulphite Cobalt Bisulphite Lead Nitrate Manganese Nitrite Copper Borate Phosphate Metal salts of organic acids (Formed by various combinations of the following:)

Anions Formate Acetate Oxalate Citrate Salicylate Phthalate Maleate Naphthol-sulphonates Ammonium Lithium Sodium Barium Calcium Zinc Iron Cobalt Lead Manganese Cop Salts of organic amines Diphenylamine trichloracetate Diphenylamine hydrochloride Diphenylamine hydrobromlde m-Nitroaniline hydrochloride Trichioroaniline hydrochloride Diphenyl amine sulphate Dlaminodiphenyl sulphate Aniline sulphate Amlno-azo-benzene sulphate e24 diamino-diphenyl sulphide Aniline hydrochloride Inorganic acids Carbonic acid Hydrochloric acid Hydrobromic acid Hydriodic acid Sulphuric acid Sulphurous acid Hydrosulphurous acid Hydrosulphuric acid Thiosulphuric acid Nitric acid Nitrous acid Boric acid Phosphoric acid Hydrocyanic Thiocyanic i Chlorsulphonic Organic acids Tartaric acid Maleic acid Acetic acid Oxalic acid Salicylic acid Phthalic acid Citric acid Trichloracetic acid Naphthenic acids d 7 Metal alcoholates Sodium amylate Two-radical compounds A. Containing nitro-grou Nitrobenzene o-Nitrophenol p-Nitrophenol B Dinit'robenzene Nitro -chloro-benzene Dinitro-chlorobenzene Dinltroaniline p-Nitro-acetanilide Nitrocresol carbonate m-Nitroaniline hydrochloride Ethyl thioether of z-nitrobenzene Ethyl thioether of 2:4 dinitrobenzene Ethyl thioether of nitro-aminobenzene 2:4-dinltrobenzene Nitro-aminobenzene B. Containing sulphogroup Benzene sulphonic acid p-Toluene sulphonic acid 2:5 dlchlorobenzen sulphonic acid m-Xylidine sulphonic acid p-Toluidine-m-sulphonic acid Naphthalene 2:6 sulphonic acid Beta-naphthol 1:5 sulphonic acid Beta-naphthol 3 6 8 sulphonic acid Beta-naphthylamine 3 6 8 trisulphonic acid 2:11 naphthylamine sulphonic acid 2:6 naphthylamine sulphonic acid 2-phenylamine-8-naphthol-6-sulphonic acid Methyl-p-toluene sulphonate .Ethyl chlorosulphonate Benzene sulphonyl' chloride p-Toluene sulphonyl chloride Naphthalene-l-sulphonyl chloride Dimethyl sulphate Diaminodihydroxy anthraquinone disulphonic acid aeiaeie d Organic esters of inorganic acids Triphenyl phosphate Tricresyl phosphate and other. alkylphenyl phosphates Nitrocresyl carbonate Ethyl chlorosulphonate Dimethyl sulphate Peroxides Barium peroxide Magnesium peroxide Benzoyl peroxide I have found certain groups of modifying merit of alkyd resinsfor instance, the organic halo-compounds.

Hereinafter examples are given of the treatment of alkyd resins with modifying agents sefull in accordance with the present invention, but before introducing specific examples, reference is now made to the treatment conditions employed.

TREATMENT Connrrrons Although the treatment conditions may be varied in accordance with a number of factors such as the particular alkyd being treated, the

the treatment temperature should be considerv ably above room temperature, and usually from about 200 C. up to about the-boiling point or decomposition point ,of the alkyd resin. In most cases the temperature should not be above about 300 C., and for many purposes treatment between about 270 C. and 290 C., has been found effective.

Increase in temperature is usually accompanied by more rapid and/or more extensive modificationalthough as just noted, the temperature is desirably kept below the point at which any decomposition occurs.

The duration of the heating will again depend somewhat on the materials used and the results desired. Usually the heating should be continued at least until thorough dispersion of the treating agent is obtained. Ordinarily it is found that treatment for a period of at least thirty minutes is required for this purpose and frequently the treatment should be. continued for several hours, for instance, up to about three or five hours.

The quantity of m0dlfying agent employed also depend somewhat on the alkyd being treated, on the modifying agent selected and on the particular characteristics desired. For various purposes a relatively wide range is usable, forvacuum may be applied. Introduction of certain gases into the reaction vessel, blanketingthe surface of the batch may also serve to exclude air.

agents to be particularly effective in the treatlected from various of the groups which are use-.

Exsmrms A number of examples of the modification of 8 reached and the product formed a clear heavy bodied oily material when cooled, dissolving easily in mineral spirits.

Each of the examples employed the foregoing long oil alkyd as starting material. The examples were all carried out under similar conditions, there being certain variations as is indicated in the table of comparative experiments below.

In all cases the resin and modifying agent were heated in a flask and CO: was introduced into the flask to form a blanket at the surface of the batch.

Table of comparative experiments Agent Percent ig Color (Hellige) Viscosity (Gardner) Acid No.

1 p-Tclusnesulphonicacid...- t zhmtzsog Blaukl Paste Not taken, 2 pl m p l 5 fi gfgg vmy viscous 3 3 iggggiggi 'Iurbidbrowngranuleri. Paste.-. Do, 4 Tri-chloro-acctic acid 5 clears H Chloralhydrate s 2 hrlemmIIIII Clesrll z-1 2111'. at 280 Brown turbid4 Paste Not taken.

g 2hr. --;do D 8 Tetra-ch oro-resor 5 at 2-5 20.8 9 Di henyl-amine 5 31 m: Z-ltoZ-2 7,3, l0 pitrophenol 6 Very viscous Nottakan, A (Atlkyglm F9581 without any Moderately viscous 011.-.. 8,0,

' 1'68 en l n (Heated without agent) {};;',-,:f;,g;,. z-2 5.4.

alkyds are given herebelow, all of these examples 7 having been carried out with the same alkyd resin, so as to give comparative results. The alkyd resin was prepared in accordance with the following.

First, a resin of medium oil length was prepared in accordance with the following formulation:

' Gm. Phthalic anhydride 1,560 Linseed oil fatty acids 1,008 Soya bean oil fatty acids 672 Glycerine 912 In the above formula 1.75 mols (260 parts by weight) of phthalic anhydride was used for 1.00 mol .(280 parts by weight) of fatty acids. of which 60% was linseed oil fatty acids and 40% soya bean oil fatty acids. 1.65 mols (152 parts by weight) of giycerine was used.

The foregoing medium oil alkyd was then diluted with linseed oil to yield along all alkyd, the following procedure beingemployed for that pur-' pose.

1800 gms. of the above medium oil length alkyd Iresin and 1800 gins. of alkali refined linseed oil were heated together in an aluminum kettle to products of Examples 1, 2, 3, 6, 7 and 10 were not fully compatible with mineral spirits, the others formed satisfactory solutions- The products of Examples 4, 5, 8, and 9 were very good with respect to clarity and color.

Subsequent agitation of the materials containing the products of Examples 1 and 10 yielded satisfactory solutions.

The products of Examples 3, 6 and '7 formed soap-like compounds, which compounds may have been salts of phthalic acid, having reduced solubility both in mineral spirits and also in that portion of alkyd resin which is still in ester form.

The treatment with tetra-chloro-resorcinol (Example 8) indicated considerable acceleration of bodying time in the preparation of the modifled resin.

A test for solubility was also made on the products of Examples 1 and 10 in Solvesso No. 2, and these displayed satisfactory solubility characteristics in Solvesso No. 2.

Still further, the mineral spirits solutions with the products of Examples 4, 5, 8 and 9 were tested for drying properties after adding 0.03% cobalt, 0.3% lead and 0.02% manganese drier. These tests showed that the solutions containing the products of Examples 4, 5 and 8 were appreciably superior to a similar test which was made on the product of Example B above, the solution containing the product of Example 5 being the best of the group.

The drying test on the solution containing the product of Example 9 indicated that the modifyingagent, (diphenyl-amine) retarded drying, as

170 0., where a complete mixture of both was compared h the Bl nk VARIABLE AND SUPPLEMENTAL TREATMENT CONDITIONS In addition to treatment at various different pressures, as above noted, the process of modification may be carried out in the presenc of various gases, such for instance, as CO2, S02, H28 and nitrogen. Such gases may either b bubbled through th reaction mass or may be employed as a blanket upon the surface of the reaction mixture, and may be used for their supplemental effect upon the primary treatment taking place.

The modifying agent may, if desired, be produced in situ, by introducing materials which will react under the conditions of treatment to produce the modifying agent desired. Various of the agents may also be used incombinations, or sequentially.

It is further to be noted that in general increasing any one or all of the variables: namely, temperature, time of treatment and percentage of modifying agent, increases the extent of modification. It will be understood that the foregoing is a general rule normally applicable within the ranges of'operation above indicated, although, as to at least some variables, there may be limits beyond which the general rule does not apply. For instance, excessive increas in temperature may substantially alter the character of the process. I

The modified product of this invention may if desired, be subject to other treatment, depending upon the use for which it is intended. Thus, for

example, the modified products may be vulcanized with sulphur.

Light treatment and wave treatment of various types also influence the reaction, for instance,

' treatment with visible light, ultra violet light or and also to certain other prior applications mentioned herebelow, all of which disclose certain features in common with the present application-to wit: Serial No. 359,425 (now Patent No. 2,213,944); Serial No. 446,172 (now 'Patent No. 2,213,943); Serial No. 446,170 (now Patent No. 2,234,949); Serial No. 370,733 (now Patent No.

2,083,550); and Serial No. 143,786 (now Patent No. 2,189,772).

Some of the modifying agents may act as dissolution promoting agents, as described in various of my prior applications and also in my issued Patent No. 2,293,038.

In the art of alkyd resin manufacture it is a known fact that 1 mol glycerine is never able to esterify with the theoretical quantity of 1 mols of phthalic anhydride. Instead the quantity of phthalic anhydride is usually in the range of 1.1 to 1.3 mols of phthalic anhydride foreach mol of glycerine. The phthalic anhydride is completely esterifled under such circumstances, as the acid value of the resin is low, but the glycerine molecules have some free hydroxyl groups left. On the other hand 1 mol of glycerine esterifieswith the theoretical quantity of 3 mols of fatty acids. Therefore when theoretical yields of alkyd resins are figured, it is customary to assume, that each mol of phthalic anhydride will liberate 1 mol of water and that excess OH-groups of the additional glycerine present remain unchanged. 1 mol of glycerine and 3 mols of fatty acids will liberate 3 mols of water of esterification.

Based on these well known facts, the constitution of the resin used in the examples of this specification is as follows:

In the "first step resin of the examples 1680 grams of fatty acids are used, being equivalent with about 6 mols of fatty acids (molecular weight of fatty acids being about 280). These fatty acids combine with 2 mols of glycerine, i.,e., 184 grams, yielding 1756 grams of glyceride and 108 grams of water of esterification. The phthalic'anhydride combines with the rest of the glycerine, forms 186.3 grams of water of esterification and yields 2101.7 grams of glycerol phthalate. The theoretical yield of resin is 3,857.7 grams and the fatty acid glyceride in same is 45.50%. This resin i extended with equal weight'of oil, so that the long oilalkyd, forming the starting point of they examples has approximately 27.25% glycerol phthalate and 72.75% fatty acid glyceride.

Iclaim:

1. A process in accordance with claim 3 in which the heating is effected under vacuum.

2. A process in accordance with claim 3 in which the temperature of treatment is between about 270 C. and 290 C. v

3. A process for altering the properties of long oil alkyd resins which comprise about 73% fatty oil acid glycerides and about 27 glycerol phthalate, which process comprises the incorporation in the long oil alkyd resin of from about 0.5 7., to about 10% of p-toluene sulpho chloride and heating the mixture to a temperature between about 260 C. and the boiling or decomposition point of the mixture, whichever is lower, until a material is produced which manifests a substantial increase in viscosity, as compared to the same long oil alkyd resin heated in the same way but without th incorporation of the p-toluene sulpho chloride.

LASZLO AUER. 

